1. Field of the Invention
The present invention relates to a jog dial emulation input device for use in a computer or the like for performing jog dial inputs such as for example, moving a cursor by making substantially circular strokes with a finger tip an the surface of the input device.
2. Description of the Related Art
A user using a computer or the like often gives a command for varying a parameter bidirectionally (e.g., up/down, left/right, increase/decrease, dark/light, positive/negative). For example, in order to select an article (e.g., a command or a choice) from a menu list including a number of articles arranged horizontally or vertically on a display screen, the user is required to move a selection cursor (i.e., pointer) via a mouse horizontally or vertically to the desired article. When drawing a picture on a display screen, it may be necessary to move the pointer exclusively in one direction (e.g., horizontally or vertically). Or, when setting a parameter such as, for example, a clock, font size, counter, thermostat, response parameter of the mouse, etc., the user may open a dialog box or the like and adjust (e.g., increase/decrease) the parameter in the dialog box. The following are other examples of operations where a bidirectional parameter is varied:
Scrolling the display upward/downward; PA1 Enlarging/shrinking the display; PA1 Moving video image frames forward/backward; PA1 Adjusting the contrast, brightness, focus, tint, color, etc., of the display; PA1 Adjusting the volume, tone, stereo balance, etc., for sound; PA1 Selecting a channel on a TV (television), radio, etc.
For performing the above operations via a keyboard, the user can press one of a set of direction keys (e.g., arrow keys) so as to move the cursor or to increase/decrease a value or parameter. By using a mouse, the user can move the pointer/cursor by moving the mouse on a mouse pad in order to drag a scroll box up/down along a scroll bar to increase/decrease the value or parameter; or click an arrow box to increase/decrease the value or parameter.
Japanese Laid-Open Patent Publication No. 7-104964 describes an invention where an article is selected from the menu list using a stylus pen or the like. A gesture recognition area is provided for each article on a display screen. When the stylus pen is located in one of the gesture recognition areas, gestures of the stylus pen are recognized, thereby selecting an article associated with the region.
Japanese Laid-Open Patent Publication No. 6-12493 describes an invention where gestures of a stylus pen, a mouse or the like are recognized based on a DP (Dynamic Programming) matching method, which has been employed in, for example, voice recognition.
A jog dial input device has also been proposed as an input device specially designed for the bidirectional adjustment of a parameter. As shown in FIG. 24, the jog dial input device includes a jog dial 21 rotatably attached to a main body, and a concave portion 21a provided at an eccentric position on the jog dial 21. The user places his finger tip A on the concave portion 21a and rotates the jog dial 21, thereby generating jog dial pulses in accordance with the rotational direction he is moving the jog dial (e.g., two pulses having a phase lead or a phase delay depending an the rotation direction). The jog dial pulses are sent to the computer and received by a device driver of the computer which determines the direction of rotation (i.e., clockwise or counterclockwise) of the jog dial 21. The determined rotation direction is sent to an application program or the like which varies a bidirectional parameter according to the direction of rotation. By using the pulses generated by the jog dial as X-/Y-pulses (indicating relative changes in X-/Y-directions, respectively), it is also possible to control mouse location data. The amount by which a bidirectional parameter is varied is represented, for example, by the number of jog dial pulses. The method of varying a bidirectional parameter utilizing the clockwise/counterclockwise rotation generated by the jog dial input device has been employed, for example, in moving video image frames forward/backward and is believed to desirably match the human's thought process.
However, there is a problem in giving a command for varying a bidirectional parameter, for example, by pressing an arrow key on the keyboard. That is, when giving a long-stroke command to move the cursor to a relatively distant position or to vary a bidirectional parameter by a relatively large amount, the user has to repeatedly press the key or hold down the key for a long time to engage the key repeat function. Such an operation may be considerably bothersome.
When using a mouse for giving a long-stroke command for varying a bidirectional parameter by a large amount, the user has to move the mouse over a long distance or quickly (when the response parameter of the mouse is automatically adjusted). Moving the hand holding the mouse over such a long distance or so quickly may be a bothersome operation. Moreover, such a long mouse move may not be complete within the mouse pad area. For example, when the mouse reaches the edge of the mouse pad area during a mouse move, the user has to lift up the mouse and place it at the opposite edge of the mouse pad area, which is quite bothersome. Furthermore, when clicking an arrow box or the like on the display screen to vary a value or other bidirectional parameters (e.g., for darkening/lightening colors), the user has to repeatedly press the mouse button or hold down the mouse button for a long time. Such an operation is as bothersome as the above-described keyboard operation.
Using a stylus pen on a tablet provided separately from the display screen is just as bothersome as the mouse operation. FIG. 25 shows a stylus pen operation described in Japanese Laid-Open Patent Publication No. 7-104964, where a stylus pen 22 is operated on a separately-provided tablet 23. In FIG. 25, the user is moving a cursor bar 25 from choice 1 at the top of a display screen 24 to choice 5 at the bottom. In such a case, the user has to move the stylus pen 22 over a long distance while keeping the stylus pen 22 close to or on the tablet 23. Accordingly, the user has to move the hand holding the stylus pen 22 over a long distance, or the user may have to lift up the stylus pen 22 during the move and place it at the upper edge of the tablet 23 to complete the move. Such an operation may be bothersome, too.
These problems may be substantially eliminated by employing a jog dial input device with which the user can give a command for varying a bidirectional parameter simply by rotating the jog dial 21 with the finger tip A. However, providing a computer with the jog dial input device merely for giving such a command may not be practical because the input device not only causes the user an additional cost but also requires more space, for example, on the desk where the computer is used.
Japanese Laid-open Patent Publication No. 7-104964 describes a gesture recognition of the stylus pen or the like for selecting an article. Such a gesture recognition requires complicated computations. Japanese Laid-Open Patent Publication No. 6-12493 describes a gesture recognition based on a DP matching method, where a complicated computation such as for example Expression 1 below is performed to obtain angle .theta..
(Expression 1) ##EQU1##
FIG. 26 shows a case where the stylus pen 22 or the like is moved from position P.sub.0 to P.sub.2 via P.sub.1. The move from P.sub.0 to P.sub.1 is represented by a "previous" vector (i.e., a vector of the previous move) whose components are represented by (VX.sub.0, VY.sub.0), and the move from P.sub.1 to P.sub.2 is represented by a "last" vector (i.e., a vector of the last move) whose components are represented by (VX.sub.1, VY.sub.2). Then, the inner (scalar) product of the previous vector and the last vector is expressed as Expression 2 below.
(Expression 2) EQU VX.sub.1 .multidot.VX.sub.0 +VY.sub.1 .multidot.VY.sub.0
The inner product is also expressed as Expression 3 below, where .theta. is the angle defined by the previous vector and the last vector.
(Expression 3) ##EQU2##
Assuming that Expressions 2 and 3 are equal to each other, the angle .theta. defined by the vectors can be obtained by Expression 1 above. Herein, the angle .theta. is within the range of the principal value of the inverse cosine (0.ltoreq..theta..ltoreq..pi.). The angle in the range of -.pi..ltoreq..theta..ltoreq..pi. is obtained by adding negative/positive signs of components of the outer product of these vectors expressed as Expression 4. For example, when the direction of the outer product of the vector P.sub.0 P.sub.1 and the vector P.sub.1 P.sub.2 is positive, the sign to be added is also positive. When the direction of the outer product is negative, the sign to be added is also negative. However, it is also applicable that the sign to be added is negative when the direction of the outer product is positive, and the sign to be added is positive when the direction of the outer product is negative.
(Expression 4) EQU VX.sub.1 .multidot.VY.sub.0 -VX.sub.0 .multidot.VY.sub.1
Thus, in such a gesture recognition process, a complicated computation has to be performed for each location input from the stylus pen 22 or the like. This increases the load on the processing unit and, therefore, real-time operations become difficult to ensure.